In order to characterize the pharmacological role of the crude polysaccharide fraction in kampo-hozai, we chose 4 kinds of kampo-hozai, Shosaiko-to, Daisaiko-to, Hachimi-jio-gan and Hochu-ekki-to, and studied the effects of their crude polysaccharide fractions on nitric oxide (NO) production by 3% thioglycollate-induced murine peritoneal macrophage. Oral administration of these fractions for 7 d augmented lipopolysaccharide (LPS, 0.1-10 μg/ml)-induced NO production by peritoneal macrophages. These results suggest the possibility that a crude polysaccharide fraction affect the macropharge function in most kampo-hozai.